US 8,938,877 B2Granted

Method of retrofitting a runway sign with a single LED lamp

AssigneeOsram Sylvania Inc.

InventorsThomas Tessnow, Kim Albright, Ronald E. Boyd, Jr., Aaron Plaza

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Abstract

A method of retrofitting an existing airfield runway sign with a single LED lamp. Light is produced by a linear array of white-light LEDs. A cylindrical lens is mounted longitudinally adjacent to the LEDs, and collects a central portion of the light emitted from the LEDs. A pair of inclined surfaces extend from the lateral edges of the LEDs to respective lateral edges of the cylindrical lens. The inclined surfaces have a rough surface texture and reflect light diffusely. The inclined surfaces collect a peripheral portion of the light emitted from the LEDs, and direct the reflected light toward the cylindrical lens. The LEDs, cylindrical lens and inclined surfaces are all mechanically supported by a heat sink. The replacement lamp is placed into a runway sign near its top or bottom edge, and illuminates both viewing surfaces of the runway sign simultaneously without a diffuser.

Claims12

Dependent claims

A method of retrofitting a two-sided airport runway sign (10) adjacent a runway, the runway sign (10) being rectangular in profile and emitting light through rectangular, translucent front and rear faces (11), the front and rear faces (11) being longitudinally separated by first and second opposing longitudinal edges (17, 16) and being perpendicular to the runway, the runway sign (10) including a plurality of original equipment lamps in its interior along the first and second longitudinal edges (17, 16) that are disposed in respective electrical sockets proximate the longitudinal edges (17, 16), the runway sign (10) also including a diffuser (130) in its interior adjacent one of the original equipment lamps, the method comprising:

opening the runway sign (10) to gain access to an interior of the runway sign (10);
electrically disengaging all the original equipment lamps on the first longitudinal edge (17) of the runway sign (10);
removing the diffuser (130) from the interior of the runway sign (10);
securing a single LED lamp (1) in one of said electrical sockets, the single LED lamp (1) having a plurality of spaced LEDs (2);
closing the runway sign (10) without reinstalling the removed diffuser (130) adjacent the single LED lamp (1);
energizing the single LED lamp (1) through the electrical socket to provide illumination to both the front and rear faces (11) of the runway sign (10) simultaneously without directing light through the diffuser (130), the illumination having average illuminance values between 108 and 323 lux at the front and rear faces (11);
and
operating the runway sign (10) to guide aircraft on said runway.

5 more elements

Dependencies are inferred from the claim text.